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ETRO_SSN583
Level 9
Level 9
100 sign-ins 5 likes given 1000 replies posted

When the clock is stipulated < 1 Mhz the timing diagram is nuts.

pastedImage_0.png

Here its is at 1 Mhz

pastedImage_1.png

Regards, Dana.

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1 Solution
DheerajK_81
Moderator
Moderator
Moderator
First comment on KBA First comment on blog 5 questions asked

Hello Dana,

Yes, I verified this. The GraphicsLCDIntf timing diagram is wrong when the frequency is less than 1MHz. I will create an internal ticket to fix this.

The timing diagram seems to be taking the input clock frequency value to be MHz no matter what you set in the clock component. This explains why you see 2ns when you set the clock to 500KHz. It is treating it as 500MHz. But I believe this shouldn't be a blocker for you.

Most of the display drivers have the read and write cycles in the order of ns, so the clock frequency is a magnitude of MHz. Can you let me know which display driver you are interfacing with? Please use the clock frequency set to MHz and interface with your display driver.

Regards,
Dheeraj

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5 Replies
DheerajK_81
Moderator
Moderator
Moderator
First comment on KBA First comment on blog 5 questions asked

Hello Dana,

Yes, I verified this. The GraphicsLCDIntf timing diagram is wrong when the frequency is less than 1MHz. I will create an internal ticket to fix this.

The timing diagram seems to be taking the input clock frequency value to be MHz no matter what you set in the clock component. This explains why you see 2ns when you set the clock to 500KHz. It is treating it as 500MHz. But I believe this shouldn't be a blocker for you.

Most of the display drivers have the read and write cycles in the order of ns, so the clock frequency is a magnitude of MHz. Can you let me know which display driver you are interfacing with? Please use the clock frequency set to MHz and interface with your display driver.

Regards,
Dheeraj

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Hi, I am using the ILI9341 display driver. This is a work in progress, have not yet

been able to get it to run a display, so slowing down clock to see if that’s what

the problem is.

Thanks for reply Dheeraj.

Regards, Dana.

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If you don't have an analyzer, you can upload the project here. I'll test at CY8CKIT-042 (no LCD ) connect the analyzer and post a screenshot .

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I do have logic analyzer, so all set. Thanks for the offer. I think my problems

are with getting the LCD controller configured properly.

Regards, Dana.

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usually the easiest test is to read the ID (send the  command 0X04 and read the ID bytes), but for some displays this may not work.

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